The field of this invention relates to a machine for cutting envelopes, or other similar types of products, from a stack of sheet paper, and more particularly for a novel arrangement for the cutting die to facilitate quick and easy attachment and removal of the cutting die from the machine.
It is well known to employ the use of a wide variety of different sizes of envelopes which are larger than the conventional letter size envelope. These envelopes are constructed from sheet paper. In the manufacture of these envelopes, a stack of sheet paper is placed upon a winding station of an envelope cutting machine. This machine includes a working station which is movable in respect to the working platform. The working station is normally movable by means of hydraulic actuators toward and away from the working platform. The working station includes a cutting die which is to be highly sharpened so as to penetrate the stack of sheets of paper. The shape of the cutting die is precisely the shape of the particular envelope prior to the folding and enclosing of the envelope.
The conventional procedure for mounting the cutting die is as follows: Each die is normally drilled and tapped with a series of holes, generally about four to six per cutting die. These holes are to match with holes on the die supporting plate. It takes two individuals to correctly position the die on the die supporting plate. Once the die is properly positioned, the fasteners are then tightened to secure the position of the cutting die.
At this time, it is normally required to locate an ejector pad within the enclosed area of the cutting die. The purpose of the ejector pad is to prevent the cut paper blanks from sticking within the enclosed area of the cutting die. This ejector pad is to be bolted to the die supporting plate. It is to be kept in mind that the outermost edge of the cutting die is extremely sharp. In fact, it would take very little contact with the die for an individual to become severly injured. Therefore, the placing of this ejector pad on the die supporting plate is an extremely dangerous operation.
Normally, this entire operation of mounting the cutting die requires at least forty-five to sixty minutes. In any given day, upon a single envelope cutting machine, the cutting die can be replaced two to three times. This means that out of an eight hour working day, two to three hours in time is necessary to merely change the cutting dies. This is time that the machine is not working to produce envelopes.